Julie is a waitress. On the left is a log of her tips for yesterday's shift.
Amount of restaurant bill ($)Tip Amounts ($)
45.55 .................................................... 7.00
52.00 ....................................................15.00
66.00 .................................................... 6.00
24.44 .................................................... 6.00
57.90 ....................................................15.00
89.75 ....................................................23.00
33.00 .................................................... 8.00
a. Find the equation of the linear regression line. Round the slope and y-intercept to the nearest hundredth.
b. What is the slope of the linear regression line?
c. What are the units of the slope when it is expressed as a rate?
d. Based on the linear regression line, what tip would Julie receive if the restaurant bill were $120? Round to the nearest dollar.
e. Is your answer to part d an example of interpolation or extrapolation? Explain.
f. Find the correlation coefficient for this data. Round to the nearest hundredth.
g. Describe the correlation.
h. Based on the linear regression line, Julie creates a spreadsheet to compute predicted tips for any restaurant bill amount. Write the formula that can be used to compute the predicted tips in column B.